Display panel, manufacturing method thereof, and display device

ABSTRACT

A display panel and a method of manufacturing the display panel are provided. The display panel includes an array substrate, a planarization layer, a pixel defining layer, an organic light emitting device, and an inorganic layer disposed between the planarization layer and the pixel defining layer to block moisture and oxygen. An encapsulation structure of the array substrate is cooperatively formed by a combination of a first interlayer dielectric layer contained in a thin-film transistor, the planarization layer, and the inorganic layer.

BACKGROUND OF INVENTION 1. Field of Invention

The present invention relates to a display field, and particularly, to adisplay panel, a manufacturing method thereof, and a display device.

2. Related Art

In display panels, organic light emitting diodes (OLEDs) emit lightthrough organic light emitting materials of light emitting layers.Organic luminescent materials are prone to corrosion by moisture andoxygen, causing pixel shrinkage in OLED devices, thereby affecting aservice life of the display panels and product yield.

Currently, a thin-film package is usually provided in organic lightemitting devices for moisture and oxygen barrier. However, the thin-filmencapsulation can only block intrusion of moisture and oxygen from upperlayers of organic light emitting devices to light emitting layers, whilecurrent moisture and oxygen can erode the light emitting layers throughbottom structures of the light emitting layers.

In a display panel industry, in order to realize a full screen design,it is necessary to bend a flexible circuit board at a lower boundary ofa panel to be attached to a lower surface of a panel, and set a bendingarea in a terminal area, wherein an organic filling layer is providedbelow the bending area to relieve bending stress, and thus its moistureand oxygen barrier performance is pool. Therefore, the organic fillinglayer filled in the bending area and a substrate jointly constitute achannel for moisture and oxygen intrusion, causing a light emittinglayer to be easily corroded by moisture and oxygen, thereby giving riseto product defects

Therefore, it is imperative to provide a display panel, a manufacturingmethod thereof, and a display device to overcome the above-mentionedproblem.

SUMMARY OF INVENTION

The present application provides a display panel and a manufacturingmethod thereof, and a display device to overcome a problem that moistureand oxygen in a current display panel intrude an organic light emittingdevice along a substrate, an organic filling layer, a planarizationlayer, and a pixel defining layer.

To overcome the above-mentioned problems, the present applicationprovides a technical solution as follows:

In one aspect of the present invention, the present application providesa display panel, comprising an array substrate comprising a substrateand a thin-film transistor disposed on the substrate; a planarizationlayer disposed on the array substrate; a pixel defining layer disposedabove the planarization layer, wherein the pixel defining layercomprises a plurality of pixel defining elements spaced apart from eachother; an organic light emitting device disposed between adjacent pixeldefining elements; and an inorganic layer disposed between theplanarization layer and the pixel defining layer and configured to blockmoisture and oxygen; wherein an encapsulation structure for a bottom ofthe organic light emitting device is cooperatively formed by acombination of a first interlayer dielectric layer contained in thethin-film transistor, the planarization layer, and the inorganic layer.

In a display panel of the present application, the thin-film transistorcomprises an active layer disposed on the array substrate; a first gateinsulating layer disposed on the active layer; a first metal layerdisposed on the first gate insulating layer; a second gate insulatinglayer disposed on the first metal layer; a second metal layer disposedthe second gate insulating layer; the first interlayer dielectric layerdisposed on the second metal layer; and a source metal and a drain metaldisposed on the first interlayer dielectric layer; wherein an anodemetal of the organic light emitting device is electrically connected tothe drain metal through a first via hole, and the organic light emittingdevice comprises the anode metal, a light emitting layer, and a cathodelayer.

In a display panel of the present application, the first via holeextends through the inorganic layer and the planarization layer.

In a display panel of the present application, the first interlayerdielectric layer is an inorganic layer, and the planarization layer isan organic layer.

In a display panel of the present application, the display panelcomprises a display area and a bending area disposed at a side of thedisplay area, and wherein the thin-film transistor and the organic lightemitting device are disposed in the display area, and an organic fillinglayer is disposed in the bending area and extends through the first gateinsulating layer, the second gate insulating layer, and the firstinterlayer dielectric layer.

In a display panel of the present application, the display panel furthercomprises a second interlayer dielectric layer disposed between theplanarization layer and the first interlayer dielectric layer, andwherein the second interlayer dielectric layer is connected to theorganic filling layer, and the second interlayer dielectric layer andthe organic filling layer are made of a same material.

In a display panel of the present application, the display panel furthercomprises a stress buffer unit disposed in the display area, and whereinthe stress buffer unit sequentially extends through the first gateinsulating layer, the second gate insulating layer, and the firstinterlayer dielectric layer, and is connected to the second interlayerdielectric layer.

In a display panel of the present application, the first metal layercomprises a first gate metal, and the second metal layer comprises asecond gate metal.

In a display panel of the present application, the display panel furthercomprises a buffer layer disposed between the substrate and thethin-film transistor.

In another aspect of the present invention, the present applicationfurther provides a method of manufacturing a display panel, comprisingfollowing steps:

S10: providing an array substrate comprising a substrate and a thin-filmtransistor disposed on the substrate;S20: forming a planarization layer on the array substrate;S30: forming an inorganic layer on the planarization layer to blockmoisture and oxygen, and forming a first via hole in the inorganic layerand the planarization layer; andS40: forming a pixel defining layer comprising a plurality of pixeldefining elements spaced apart from each other on the inorganic layer,and forming an organic light emitting device between adjacent pixeldefining elements;

wherein a first interlayer dielectric layer contained in the thin-filmtransistor, the planarization layer, and the inorganic layercooperatively form an encapsulation structure for a bottom of theorganic light emitting device.

In a method of manufacturing the display panel of the presentapplication, the step S30 comprises pattering, by using a first maskprocess, the planarization layer to form the first via hole, wherein theinorganic layer is formed on the patterned planarization layer, andremoving, by using a second mask process, an inorganic material in thefirst via hole to form the first via hole.

In a method of manufacturing the display panel of the presentapplication, the step S30 comprises forming the inorganic layer on theplanarization layer, and pattering the inorganic layer and theplanarization layer by using a first mask process to form the first viahole.

In another aspect of the present invention, the present applicationfurther provides a display device, comprising a display panel and apolarizer, wherein the display panel comprises an array substratecomprising a substrate and a thin-film transistor disposed on thesubstrate; a planarization layer disposed on the array substrate; apixel defining layer disposed above the planarization layer, wherein thepixel defining layer comprises a plurality of pixel defining elementsspaced apart from each other; an organic light emitting device disposedbetween adjacent pixel defining elements; and an inorganic layerdisposed between the planarization layer and the pixel defining layerand configured to block moisture and oxygen; wherein an encapsulationstructure is formed by a combination of a first interlayer dielectriclayer contained in the thin-film transistor, the planarization layer,and the inorganic layer cooperatively form at a bottom of the organiclight emitting device.

In a display device of the present application, the thin-film transistorcomprises an active layer disposed on the array substrate; a first gateinsulating layer disposed on the active layer; a first metal layerdisposed on the first gate insulating layer; a second gate insulatinglayer disposed on the first metal layer; a second metal layer disposedthe second gate insulating layer; the first interlayer dielectric layerdisposed on the second metal layer; and a source metal and a drain metaldisposed on the first interlayer dielectric layer; wherein an anodemetal of the organic light emitting device is connected to the drainmetal over the first via hole, and the organic light emitting devicecomprises the anode metal, a light emitting layer, and a cathode layer.

In a display device of the present application, the first via holeextends through the inorganic layer and the planarization layer.

In a display device of the present application, the first interlayerdielectric layer is an inorganic layer, and the planarization layer isan organic layer.

In a display device of the present application, the display panelcomprises a display area and a bending area disposed at a side of thedisplay area, and wherein the thin-film transistor and the organic lightemitting device are disposed in the display area, and an organic fillinglayer is disposed in the bending area and extends through the first gateinsulating layer, the second gate insulating layer, and the firstinterlayer dielectric layer.

In a display device of the present application, the display panelfurther comprises a second interlayer dielectric layer disposed betweenthe planarization layer and the first interlayer dielectric layer, andwherein the second interlayer dielectric layer is connected to theorganic filling layer, and the second interlayer dielectric layer andthe organic filling layer are made of a same material.

In a display device of the present application, the display panelfurther comprises a stress buffer unit disposed in the display area, andwherein the stress buffer unit sequentially extends through the firstgate insulating layer, the second gate insulating layer, and the firstinterlayer dielectric layer, and is connected to the second interlayerdielectric layer.

In a display device of the present application, the first metal layercomprises a first gate metal, and the second metal layer comprises asecond gate metal.

The present application has advantageous effects as follows: the presentapplication utilizes the newly added inorganic layer disposed betweenthe planarization layer and the pixel defining layer to allow the firstinterlayer dielectric layer, the planarization layer, and the inorganiclayer to cooperatively form an encapsulation structure for a bottom ofthe organic light emitting device, thereby to prevent moisture andoxygen from intruding into the organic light emitting device from abottom of the light emitting layer, and improve a service life of theorganic light emitting device.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in the embodiments or in the priorart more clearly, the following briefly describes the accompanyingdrawings required for describing the embodiments or the prior art.Apparently, the accompanying drawings in the following description showmerely some embodiments of the present invention, and a person ofordinary skill in the art may still derive other drawings from theseaccompanying drawings without creative efforts.

FIG. 1 is a cross-sectional view of a display panel of a firstembodiment of the present application.

FIG. 2 is a cross-sectional view of a display panel of a secondembodiment of the present application.

FIG. 3 is a cross-sectional view of a display panel of a thirdembodiment of the present application.

FIGS. 4a-4d are schematic structural views with respect to a step S30 ofthe third embodiment of the present application.

FIGS. 5a-5c are schematic structural views with respect to a step S30 ofa fourth embodiment of the present application.

DESCRIPTION OF PREFERRED EMBODIMENTS

The following embodiments are described with reference to theaccompanying drawings, and are used to exemplify specific embodimentsfor implementation of the present invention. Terms about directionsmentioned in the present invention, such as “upper”, “lower”, “front”,“rear”, “left”, “right”, “in”, “out”, and “side surface” merely refer todirections in the accompanying drawings. Therefore, the used terms aboutdirections are used to describe and understand the present invention,and are not intended to limit the present invention. In the figures,units having similar structures are represented by using a samereference number.

The present application provides a display panel and a manufacturingmethod thereof, and a display device to overcome a problem that moistureand oxygen in a current display panel intrude an organic light emittingdevice along a substrate, an organic filling layer, a planarizationlayer, and a pixel defining layer.

Please refer to FIG. 1. FIG. 1 is a cross-sectional view of a displaypanel 100 of a first embodiment of the present application.

According to one aspect of the present application, the presentapplication provides the display panel 100 including an array substrate,a planarization layer 13, a pixel defining layer, an organic lightemitting device 15, and an inorganic layer 14 disposed between theplanarization layer 13 and the pixel defining layer.

The array substrate includes a substrate 11 and a thin-film transistor12 disposed on the substrate 11.

In one embodiment, a buffer layer is disposed between the substrate 11and the thin-film transistor 12, wherein a material of the buffer layerincludes one of silicon nitride and silicon oxide.

In one embodiment, in order to facilitate a bendable design of thedisplay panel 100, the substrate 11 is a flexible substrate 11. Amaterial of the flexible substrate 11 includes polyimide, and thepolyimide is an organic substance having a low moisture and oxygenbarrier performance.

In one embodiment, the thin-film transistor 12 includes:

an active layer 121 disposed on the array substrate;a first gate insulating layer 122 disposed on the active layer 121;a first metal layer 123 disposed on the first gate insulating layer 122;a second gate insulating layer 124 disposed on the first metal layer123;a second metal layer 125 disposed the second gate insulating layer 124;a first interlayer dielectric layer 126 disposed on the second metallayer 125; and a source metal 127 and a drain metal 128 disposed on thefirst interlayer dielectric layer 126; wherein an anode metal 151 of theorganic light emitting device 15 is electrically connected to the drainmetal 128 through a first via hole, and the organic light emittingdevice 15 includes the anode metal 151, a light emitting layer 152, anda cathode layer 153.

In one embodiment, the first via hole extends through the inorganiclayer 14 and the planarization layer 13.

In one embodiment, the active layer 121 includes an intermediate channelportion and a source doping area and a drain doping area disposed atboth ends of the channel portion. The source metal 127 is connected tothe source doping area, and the drain metal 128 is connected to thedrain doping area.

The first metal layer 123 includes a first gate metal, and the secondmetal layer 125 includes a second gate metal.

The planarization layer 13 is disposed on the source metal 127 and thedrain metal 128.

A material of the planarization layer 13 is an organic material forplanarizing a surface of the array substrate.

The inorganic layer 14 is disposed on a surface of the planarizationlayer 13 for blocking moisture and oxygen intrusion in a longitudinaldirection.

The first interlayer dielectric layer 126 contained in the thin-filmtransistor 12, the planarization layer 13, and the inorganic layer 14cooperatively form an encapsulation structure for a bottom of the lightemitting layer 152, thereby to prevent moisture and oxygen fromintruding into the light emitting layer 152 of the organic lightemitting device 15 from a bottom of the organic light emitting device15.

Since the first interlayer dielectric layer 126 is also made of aninorganic material, the first interlayer dielectric layer 126, theplanarization layer 13, and the inorganic layer 14 cooperatively form aninorganic/organic/inorganic encapsulation structure, thereby to becapable of providing moisture and oxygen barrier performance the same asthat of an encapsulation portion on the light emitting layer 152.

The pixel defining layer is disposed above the planarization layer 13and includes a plurality of pixel defining elements 17 spaced apart fromeach other for defining pixel areas. The plurality of pixel definingelements 17 are made of an organic material.

The organic light emitting device 15 is disposed in a pixel area betweenadjacent pixel defining elements 17.

The organic light emitting device 15 includes the anode metal 151, thecathode layer 153, and the light emitting layer 152 disposed between theanode metal 151 and the cathode layer 153.

In one embodiment, the display panel 100 includes a display area 100 aand a bending area 100 b disposed at a side of the display area 100 a.

The thin-film transistor 12 and the organic light emitting device 15 aredisposed in the display area 100 a. An organic filling layer 16 isdisposed in the bending area 100 b and extends through the first gateinsulating layer 122, the second gate insulating layer 124, and thefirst interlayer dielectric layer 126.

Since the organic filling layer 16, the substrate 11, the planarizationlayer 13, and the pixel defining layer are all made of an organicmaterial, and in the current display panel 100, the substrate 11, theorganic filling layer 16, the planarization layer 13, and the pixeldefining layer are in direct contact with each other, a channel formoisture and oxygen intrusion is thus formed. Furthermore, the inorganiclayer 14 of the present application disposed between the planarizationlayer 13 and the pixel defining layer can provide moisture and oxygenbarrier performance, thereby to prevent moisture and oxygen fromintruding into a bottom of the light emitting layer 152.

In one embodiment, the organic filling layer 16 extends through thebuffer layer, the first gate insulating layer 122, the second gateinsulating layer 124, and the first interlayer dielectric layer 126.

Please refer to FIG. 2. FIG. 2 is a cross-sectional view of a displaypanel of a second embodiment of the present application.

In one embodiment, the display panel 100 further includes a secondinterlayer dielectric layer 129 disposed between the planarization layer13 and the first interlayer dielectric layer 126, and the secondinterlayer dielectric layer 129 is connected to the organic fillinglayer 16, wherein the second interlayer dielectric layer 129 and theorganic filling layer 16 are made of a same material.

In one embodiment, the display panel 100 further includes a stressbuffer unit 18 disposed in the display area 100 a. The stress bufferunit 18 sequentially extends through the first gate insulating layer122, the second gate insulating layer 124, and the first interlayerdielectric layer 126, and is spaced apart from the second interlayerdielectric layer 129.

In one embodiment, the stress buffer unit 18 sequentially extendsthrough the buffer layer, the first gate insulating layer 122, thesecond gate insulating layer 124, and the first interlayer dielectriclayer 126, and is connected to the second interlayer dielectric layer129.

Please refer to FIG. 3. FIG. 3 is a cross-sectional view of a displaypanel 100 of a third embodiment of the present application.

According to another aspect of the present application, the presentapplication further provides a method of manufacturing a display panel100, including the following steps:

S10: providing an array substrate including a substrate 11 and athin-film transistor 12 disposed on the substrate 11;S20: forming a planarization layer 13 on the array substrate;S30: forming an inorganic layer 14 on the planarization layer 13 toblock moisture and oxygen, and forming a first via hole in the inorganiclayer 14 and the planarization layer 13; andS40: forming a pixel defining layer including a plurality of pixeldefining elements 17 spaced apart from each other on the inorganic layer14, and forming an organic light emitting device 15 between adjacentpixel defining elements 17; wherein a first interlayer dielectric layer126 contained in the thin-film transistor 12, the planarization layer13, and the inorganic layer 14 cooperatively form an encapsulationstructure for a bottom of a light emitting layer 152.

In one embodiment, in order to facilitate a bendable design of thedisplay panel 100, the substrate 11 is a flexible substrate 11. Amaterial of the flexible substrate 11 includes polyimide, and thepolyimide is an organic substance having a low moisture and oxygenbarrier performance.

In one embodiment, the thin-film transistor 12 includes:

an active layer 121 disposed on the array substrate;a first gate insulating layer 122 disposed on the active layer 121;a first metal layer 123 disposed on the first gate insulating layer 122;a second gate insulating layer 124 disposed on the first metal layer123;a second metal layer 125 disposed the second gate insulating layer 124;a first interlayer dielectric layer 126 disposed on the second metallayer 125;and a source metal 127 and a drain metal 128 disposed on the firstinterlayer dielectric layer 126, wherein an anode metal 151 of theorganic light emitting device 15 is electrically connected to the drainmetal 128 through a first via hole, and the organic light emittingdevice 15 includes the anode metal 151, a light emitting layer 152, anda cathode layer 153.

Please refer to FIGS. 4a-4d . FIGS. 4a-4d are schematic structural viewswith respect to a step S30 of the third embodiment of the presentapplication.

In one embodiment, the step S30 includes: pattering, by using a firstmask process, the planarization layer 13 to form the first via hole,wherein the inorganic layer 14 is formed on the patterned planarizationlayer 13, and removing, by using a second mask process, an inorganicmaterial in the first via hole to form the first via hole.

Please refer to FIGS. 5a-5c . FIGS. 5a-5c are schematic structural viewswith respect to a step S30 of a fourth embodiment of the presentapplication.

In one embodiment, the step S30 includes: forming the inorganic layer 14on the planarization layer 13, and pattering the inorganic layer 14 andthe planarization layer 13 by using a first mask process to form thefirst via hole.

The planarization layer 13 is disposed on the source metal 127 and thedrain metal 128.

A material of the planarization layer 13 is an organic material forplanarizing a surface of the array substrate.

The inorganic layer 14 is disposed on a surface of the planarizationlayer 13 for blocking moisture and oxygen intrusion in a longitudinaldirection.

The first interlayer dielectric layer 126 contained in the thin-filmtransistor 12, the planarization layer 13, and the inorganic layer 14cooperatively form an encapsulation structure for a bottom of the lightemitting layer 152, thereby to prevent moisture and oxygen fromintruding into the light emitting layer 152 of the organic lightemitting device 15 from a bottom of the organic light emitting device15.

Since the first interlayer dielectric layer 126 is also made of aninorganic material, the first interlayer dielectric layer 126, theplanarization layer 13, and the inorganic layer 14 cooperatively form aninorganic/organic/inorganic encapsulation structure, thereby to becapable of providing moisture and oxygen barrier performance the same asthat of an encapsulation portion on the light emitting layer 152.

The pixel defining layer is disposed above the planarization layer 13and includes a plurality of pixel defining elements 17 spaced apart fromeach other for defining pixel areas. The plurality of pixel definingelements 17 are made of an organic material.

The organic light emitting device 15 is disposed in a pixel area betweenadjacent pixel defining elements 17.

The organic light emitting device 15 includes the anode metal 151, thecathode layer 153, and the light emitting layer 152 disposed between theanode metal 151 and the cathode layer 153.

In one embodiment, the display panel 100 includes a display area 100 aand a bending area 100 b disposed at a side of the display area 100 a.

The thin-film transistor 12 and the organic light emitting device 15 aredisposed in the display area 100 a. An organic filling layer 16 isdisposed in the bending area 100 b and extends through the first gateinsulating layer 122, the second gate insulating layer 124, and thefirst interlayer dielectric layer 126.

In one embodiment, the organic filling layer 16 extends through thebuffer layer, the first gate insulating layer 122, the second gateinsulating layer 124, and the first interlayer dielectric layer 126.

Since the organic filling layer 16, the substrate 11, the planarizationlayer 13, and the pixel defining layer are all made of an organicmaterial, and in the current display panel 100, the substrate 11, theorganic filling layer 16, the planarization layer 13, and the pixeldefining layer are in direct contact with each other, a channel formoisture and oxygen intrusion is thus formed. Furthermore, the inorganiclayer 14 of the present application disposed between the planarizationlayer 13 and the pixel defining layer can provide moisture and oxygenbarrier performance, thereby to prevent moisture and oxygen fromintruding into a bottom of the light emitting layer 152.

In one embodiment, the display panel 100 further includes a secondinterlayer dielectric layer 129 disposed between the planarization layer13 and the first interlayer dielectric layer 126, and the secondinterlayer dielectric layer 129 is connected to the organic fillinglayer 16, wherein the second interlayer dielectric layer 129 and theorganic filling layer 16 are made of a same material.

In one embodiment, the display panel 100 further includes a stressbuffer unit 18 disposed in the display area 100 a. The stress bufferunit 18 sequentially extends through the first gate insulating layer122, the second gate insulating layer 124, and the first interlayerdielectric layer 126, and is spaced apart from the second interlayerdielectric layer 129.

The present application has advantageous effects as follows: the presentapplication utilizes the newly added inorganic layer disposed betweenthe planarization layer and the pixel defining layer to allow the firstinterlayer dielectric layer, the planarization layer, and the inorganiclayer to cooperatively form an encapsulation structure for a bottom ofthe organic light emitting device, thereby to prevent moisture andoxygen from intruding into the organic light emitting device from abottom of the light emitting layer, and improve a service life of theorganic light emitting device.

Accordingly, although the present invention has been disclosed as apreferred embodiment, it is not intended to limit the present invention.Those skilled in the art without departing from the spirit and scope ofthe present invention may make various changes or modifications, andthus the scope of the present invention should be after the appendedclaims and their equivalents.

What is claimed is:
 1. A display panel, comprising: an array substratecomprising a substrate and a thin-film transistor disposed on thesubstrate; a planarization layer disposed on the array substrate; apixel defining layer disposed above the planarization layer, wherein thepixel defining layer comprises a plurality of pixel defining elementsspaced apart from each other; an organic light emitting device disposedbetween adjacent pixel defining elements; and an inorganic layerdisposed between the planarization layer and the pixel defining layerand configured to block moisture and oxygen; wherein an encapsulationstructure for a bottom of the organic light emitting device iscooperatively formed by a combination of a first interlayer dielectriclayer contained in the thin-film transistor, the planarization layer,and the inorganic layer.
 2. The display panel of claim 1, wherein thethin-film transistor comprises: an active layer disposed on the arraysubstrate; a first gate insulating layer disposed on the active layer; afirst metal layer disposed on the first gate insulating layer; a secondgate insulating layer disposed on the first metal layer; a second metallayer disposed the second gate insulating layer; the first interlayerdielectric layer disposed on the second metal layer; and a source metaland a drain metal disposed on the first interlayer dielectric layer;wherein an anode metal of the organic light emitting device iselectrically connected to the drain metal through a first via hole, andthe organic light emitting device comprises the anode metal, a lightemitting layer, and a cathode layer.
 3. The display panel of claim 2,wherein the first via hole extends through the inorganic layer and theplanarization layer.
 4. The display panel of claim 3, wherein the firstinterlayer dielectric layer is an inorganic layer, and the planarizationlayer is an organic layer.
 5. The display panel of claim 2, wherein thedisplay panel comprises a display area and a bending area disposed at aside of the display area, and wherein the thin-film transistor and theorganic light emitting device are disposed in the display area, and anorganic filling layer is disposed in the bending area and extendsthrough the first gate insulating layer, the second gate insulatinglayer, and the first interlayer dielectric layer.
 6. The display panelof claim 5, wherein the display panel further comprises a secondinterlayer dielectric layer disposed between the planarization layer andthe first interlayer dielectric layer, and wherein the second interlayerdielectric layer is connected to the organic filling layer, and thesecond interlayer dielectric layer and the organic filling layer aremade of a same material.
 7. The display panel of claim 6, wherein thedisplay panel further comprises a stress buffer unit disposed in thedisplay area, and wherein the stress buffer unit sequentially extendsthrough the first gate insulating layer, the second gate insulatinglayer, and the first interlayer dielectric layer, and is connected tothe second interlayer dielectric layer.
 8. The display panel of claim 2,wherein the first metal layer comprises a first gate metal, and thesecond metal layer comprises a second gate metal.
 9. The display panelof claim 1, further comprising a buffer layer disposed between thesubstrate and the thin-film transistor.
 10. A method of manufacturing adisplay panel, comprising following steps: S10: providing an arraysubstrate comprising a substrate and a thin-film transistor disposed onthe substrate; S20: forming a planarization layer on the arraysubstrate; S30: forming an inorganic layer on the planarization layer toblock moisture and oxygen, and forming a first via hole in the inorganiclayer and the planarization layer; and S40: forming a pixel defininglayer comprising a plurality of pixel defining elements spaced apartfrom each other on the inorganic layer, and forming an organic lightemitting device between adjacent pixel defining elements; wherein afirst interlayer dielectric layer contained in the thin-film transistor,the planarization layer, and the inorganic layer cooperatively form anencapsulation structure for a bottom of the organic light emittingdevice.
 11. The method of manufacturing the display panel of claim 10,wherein the step S30 comprises: pattering, by using a first maskprocess, the planarization layer to form the first via hole, wherein theinorganic layer is formed on the patterned planarization layer, andremoving, by using a second mask process, an inorganic material in thefirst via hole to form the first via hole.
 12. The method ofmanufacturing the display panel of claim 10, wherein the step S30comprises: forming the inorganic layer on the planarization layer, andpattering the inorganic layer and the planarization layer by using afirst mask process to form the first via hole.
 13. A display device,comprising a display panel and a polarizer, wherein the display panelcomprises: an array substrate comprising a substrate and a thin-filmtransistor disposed on the substrate; a planarization layer disposed onthe array substrate; a pixel defining layer disposed above theplanarization layer, wherein the pixel defining layer comprises aplurality of pixel defining elements spaced apart from each other; anorganic light emitting device disposed between adjacent pixel definingelements; and an inorganic layer disposed between the planarizationlayer and the pixel defining layer and configured to block moisture andoxygen; wherein an encapsulation structure is formed by a combination ofa first interlayer dielectric layer contained in the thin-filmtransistor, the planarization layer, and the inorganic layercooperatively format a bottom of the organic light emitting device. 14.The display device of claim 13, wherein the thin-film transistorcomprises: an active layer disposed on the array substrate; a first gateinsulating layer disposed on the active layer; a first metal layerdisposed on the first gate insulating layer; a second gate insulatinglayer disposed on the first metal layer; a second metal layer disposedthe second gate insulating layer; the first interlayer dielectric layerdisposed on the second metal layer; and a source metal and a drain metaldisposed on the first interlayer dielectric layer; wherein an anodemetal of the organic light emitting device is connected to the drainmetal over the first via hole, and the organic light emitting devicecomprises the anode metal, a light emitting layer, and a cathode layer.15. The display device of claim 14, wherein the first via hole extendsthrough the inorganic layer and the planarization layer.
 16. The displaydevice of claim 15, wherein the first interlayer dielectric layer is aninorganic layer, and the planarization layer is an organic layer. 17.The display device of claim 14, wherein the display panel comprises adisplay area and a bending area disposed at a side of the display area,and wherein the thin-film transistor and the organic light emittingdevice are disposed in the display area, and an organic filling layer isdisposed in the bending area and extends through the first gateinsulating layer, the second gate insulating layer, and the firstinterlayer dielectric layer.
 18. The display device of claim 17, whereinthe display panel further comprises a second interlayer dielectric layerdisposed between the planarization layer and the first interlayerdielectric layer, and wherein the second interlayer dielectric layer isconnected to the organic filling layer, and the second interlayerdielectric layer and the organic filling layer are made of a samematerial.
 19. The display device of claim 18, wherein the display panelfurther comprises a stress buffer unit disposed in the display area, andwherein the stress buffer unit sequentially extends through the firstgate insulating layer, the second gate insulating layer, and the firstinterlayer dielectric layer, and is connected to the second interlayerdielectric layer.
 20. The display device of claim 14, wherein the firstmetal layer comprises a first gate metal, and the second metal layercomprises a second gate metal.